Interesting section here: "Some GO lines will not have sufficient capacity – Many of the GO Rail lines to the downtown will be at capacity, even with the improvements included in the reference network. From the north, passenger demand is forecast to exceed the capacities of the Barrie and Stouffville GO lines. Ridership on the Lakeshore East GO line is estimated to significantly exceed the future capacity of the line."
They then go on to say: "Given the key issues detailed above, the DTRES study considered rapid transit infrastructure alternatives along two primary corridors: a “downtown relief†corridor creating a new travel option for passengers on the Bloor-Danforth subway line to travel into the downtown (DRL); and a rapid transit alternative along the Lakeshore rail corridor providing more rapid transit capacity into the downtown from south Scarborough and south Etobicoke. In each case, the alternatives are envisioned as high-capacity, grade-separated rapid transit similar to a subway service, operating as part of the TTC system with current TTC fares."
Are they expecting that the electrification of the Lakeshore East corridor will not provide sufficient passenger capacity, so the TTC needs to run a duplicate service along the corridor? That seems pretty strange to me, considering that Lakeshore West currently has a higher ridership, but they don't talk about any capacity concerns along that corridor. Theoretically if it's being run as a single through-line the capacity of each corridor would be identical, no? Assuming the same number of electrified tracks are being used, which I'm sure they would be.